Defrosting refrigerating apparatus



Nov. 4, 1952 G. s.'M :c| oY 2,616,272

oEFRos'TING REFRIGERATING APPARATUS Filed Feb. 28, 195o 2 k 2 2 A 2 2 2 k WITNESSES: l INVENTOR n Graham S. McCloy BWM V ATTORNEY Patented Nov. 4, 1952 PATENT ofrrifcaA '524616,2'72' .DE'FROSTlNGrRfEFRIGERATING :APPARATUS Grah'a'i SQ 'McCloy`, Springfield, Mass., assigner' to Westinghouse Electric Corporation, East" Pittsburgh; Pa., a-'corporationvof- Pennsylvania ApplicatiomFebrual-y 28, 1950,'.Ser-ia-1No. 146,6881

Videla retrigerating and clef'ros'ting mechanism wlichlis'o'f'low -co'st and trouble Ifree.

'These' 4and other objects .are effected lby the invention-as .will "beappa'rent' from the' following Y description-arid claims taken in connection with the' accom)da'nyingA drawing; forming. a part oil.'

tlii's application, 'in which the single Ygure of the drawing` isi-a vertical sectional schematic view cfa-refrigerator.' showing the' refrigerating apparatus' of `this invention.

Intnedrawinathe reference'numeral In' desighates'v a' 'refrigerator'. cabinet having, Aa 'food-stora'g'ec'ompartment Illin th'eulpper portion thereof and' a 'machine compartment I4 'below the`food storage compartment.- The foodfstorage' compartment is pro'vi'ded with thermal' 'insulation I5 and Y.includes a door IGI 4The coolingelement ofthe.v food" storage compartment .I2 comprilsesfa tube I'l'l'iaving an entrance' ,portion I8 embedded in the,'thermalinsulation I5 .o'fthel cabinet. .IILA 'l'liereniainder'o the cooling vunit .I.1'i's located in'theupper portion o'fthc fod'storage compartmentr 12'" and comprises: several 'horizontalrpassages. The tube I1. emptieslinto .anchambery 2'2 which forms :botha refrigerant header for the tube 1I Tand. a 'trap wherein refrigerant liquid. -is stored duringfthe- .refrigerating Iprocess of the apparatus; The. chamber y22 isinheat transfer relationship withan-portion .2.-3- .ofthe :tu-be -I-1 located` near the entrance -endithereo A-suction-conduit n2-l 5connectstlfirough a tube 2'5and a. valve- 2=8. Withfan. upper 'portion-of the chamber- 4232v .andy through a-v tube` 30. withthe lower portion thereof. The suctionconduit' 24 communicates With fasealed `casing; 1254 which enclose'siaicompressor 21 and an-electrio .motor 29 for drivingf'the'compressor 21. The inlet port 1l. of' the compressor communicates with the interior of the casing 25 and the exhaust por-t 33 of the compressor 21V connects through a hot vapor. linev 34 with anv air cooled condenser 36. The vapor li'ne r34 is located vin heat-transfer relationshipwith al-portion 35 of .the suction conduit 24. .Theoutlet. of the condenser 3.6 communicate's through a capillary impedance tube `(Cl. S21-@117.155)

2, 4U with the entrance portionIS'oifthe tube 11. A. portion 45| of the' capillary tube" 4U is? in heattransfer relationship with the portion 43 of the suction conduit '24 to improve the efli'c'iency of the refrigerating system.

The electric motor v.receives power from the lines 42 through the conductors 44. .A thermostatic switch 46 is located. in one of. the conductors 44 and. hasa temperature. sensitive. .bulb 48 Yincontact with the tube. I1.y .Anelectriaheater is located. inthe thermal vinsulationl ofthe l cabinet IIJ to heat the entrance portion. .IB of` the .tube I1.. Theelectric .heater.50receives its power. through leads `52-l from leads 42'.- lA switch 54 -is located,` in one..y oi"r .the leads .52.1V

Operation;

When both the'valve 28 and the' switch 54 are'v open, the' refrigeratingy .apparatus of this' invention operates to refrigerate the :food storage' chamber I2. Refrigerant liquid is then supplied to 'the Vtube 'I1 `fromy the condenserfil' through the capillary tube` 4G. Themajor' por# tion of. the liquidvaporize's'in .thetube l1 toA cool itl'while the remainder of the liquid' fills" 'the chamber 22` to the level A A. The" chamber 22 acts as 'a refrigerant "header to allow 'thei'ref'rigerant Yvapor to separate. fromthe .refrigerant liquidy and also traps the liquid; The refrigerant' vapor'is withdrawn from 'the chamber`22 by the con'ipresso'rv `21 through'the tube' 26; the'l valve` 28; andthe suction conduitzp The compressor. 2T compresses vthis vapor 4and discharges `itthrough the hot vapor line' 3'4 into` vthe condenser; '3l' `vwherein thev'apor'is'condensed to a'liquid. TheV thermostatic switch 4t' Vn'i'aintain's thetube I T .at

- substantially a `constant temperature belowifreeze v sor 2`1'throug`h the tubes 39 and '24; 'This refrigerant liquid flows downwardly through Athe suction conduit 24 into the portion"thereof'wlich' is in heat-exchange .relationship with the hot vapor line 3.4. The hot vapor linen 34' and' also the conduit portion '35 are at a 'highert'emperakture than the cooling Ytube .Ilso that the .vapor ,pressure in the tube I1 and the suction conduit 2"4 is raised to that corresponding. -to theteml-` perature ofthe liquidY refrigerant in the conduitv VV1;Jor`t'io'n'3'5. The 'refrigerant liquid Willthus noV longer vaporize in the tube I1 and instead vaporizes in the conduit portion 35. The refrigerant liquid owing in the tube I1 is heated by the heater 50 to aid in melting the frost on the tube l1 and the chamber 22.

In order to insure that the chamber 22 is emptied of refrigerant liquid to the level of the inlet of the tube when the valve 28 is closed, the chamber 22 is placed in heat-transfer relationship with the portion 23 of tube I1. When the cabinet IB is being refrigerated, the chamber 22 is normally the coldest portion of the cooling system l1, 22. This is caused by the fact that the suction pressure on the chamber 22 is lower than that on the tube l1 by the frictional drop of pressure in the tube I'I. At such a low temperature, there is a tendency for the vapor in the chamber 22 to condense into a liquid whenv the suction pressure in the conduit 24 is raised. The condensation of this -vapor tends to withdraw the refrigerated liquid from the conduit portion `and thereby retard the defrosting action. The portion 23 ofthe tube I1 prevents this by warming the chamber 22 so that the vapor therein does not condense.

M o dif cations While the invention has been shown in but one form, it will be obvious to those skilled inthe art that it is not so limited, but is susceptibleof variousy changes and modifications Without departing from the spirit thereof. The chamber 22, may be warmed by means other than the conduit portion 23, for example, by an electric heater. Heat, absorbing fins may also be placed on the chamber 22 so that it absorbs more heat from the storage chamber and does not become the coldest portion of the cooling system l1, 22. lhejchamber 22 need not be placed at the discharge end of the tube I1 but can be placed intermediate the ends of this tube I1. It may also be placed in the suction conduit 24 if precautions are taken to prevent excessive Vaporization of the refrigerant liquid trapped in the chamber 22. The tube portion 35 may be heated by any means other than the hot Vapor line 34 s 'uch as, for example, by an electric heater.

. The heater 5i) at the entrance portion i3 of the tube l1 is desirable but not essential. Its use accelerates the melting of the frost on tube Hand header 22 by raising the temperature of the refrigerant liquid leaving the tube portion I 8 to above the temperature at which the refrigerant liquid leaves the capillary tube 40.

The valve 23 and the tubes 26 and 30 are merely a contrivance to selectively withdraw either refrigerant vapor or refrigerant liquid from the chamber 29 and any other device which accomplishesthis purpose may be substituted therefor.

Conclusion If desired, the refrigerant from either an upper portion or a lower portion of said chamber into said conduit, a condenser. a hot vapor line connecting the outlet of said compressor with the inlet of said condenser, said hot vapor line being in heat-transfer relationship with a portion of the suction conduit, a liquid line including a flow impeding device for connecting the outlet of said condenser with the inlet of the evaporator, a heater for heating a portion of the tube near the entrance thereof, means for controlling said heater, a portion of said tube subsequent to said heated portion being in heat-exchange relationship with said chamber, and a quantity of refrigerant liquid in said circuit sufficient to flll the lower portion of said chamber during a refrigerating operation of said circuit.

'2. A refrigerating circuit for selectively refrigerating or defrosting an evaporator, said circuit comprising a tube forming an evaporator, a chamber connected to the outlet of said tube, a compressor, a suction conduit connecting said chamber with the inlet of said compressor, said suction conduit having two inlets one of which communicates with an upper portion of said chamber and the other with a lower portion thereof, valve means for directing the refrigerant entering said conduit selectively through either of the said inlets, a condenser, a hot vapor line connecting the outlet ofsaid compressor with the inlet of said condenser, said hot vapor line being in heat-transfer relationship with a portion'of the suction conduit, a liquid line including a flow impeding device for connecting the outlet of said condenser with the inlet ofthe evaporator, a heater for heating a portion of the tube near the entrance thereof, means for controlling said heater, a portionof said conduit subsequent to said heated portion being in heatexchange relationship with said chamber, and a quantity of refrigerant liquid in said circuit sufficient to fill said chamber to above the suction tube inlet communicating with the lower portion of said chamber during a refrigerating operation of said circuit. v

3. A refrigerating circuit for selectively refrig-A erating or heating an evaporator, said circuit comprising an evaporator having an. inlet and an outlet, a compressor, a condenser for receiving compressed refrigerant vapor from saidv com-y pressor, a liquid line including apressure-reduc-A ing device for conducting refrigerant liquid from said condenser to the inlet of said evaporator, a

suction conduit connecting the outlet ,of said evaporator withV the inlet of said compressor,

,means for heating a portion of said suction conduit, a storage vessel located in said circuit intermediate the Ainlet of said evaporator and the heated portion of the suction conduit andar; ranged to trap refrigerant liquid, means forl re-A leasing said trapped refrigerant liquid, and means for heating said storage vessel to prevent the condensation of refrigerant therein during the time refrigerant liquid is being released fromv said storage vessel.

4. The refrigerant circuit defined in claim 3' including means for heating the refrigerant liquid flowing in said evaporator when the re frigerant liquid is released from s aid storage` vessel. n

5.Y A refrigerating circuit for selectively refrigerating or' heating an evaporator,` said circuit, comprising an evaporator having an ,inletA and an outlet, a ccmpressor, a condenser for receiving compressed refrigerant vapor` from said com pressor, a liquid line including a pressure-reducing device for conducting refrigerant liquid from said condenser to the inlet of said evaporator, a suction conduit connecting the outlet of said evaporator with said compressor, means for heating a portion of said suction conduit, storage means located in said circuit intermediate the inlet of said evaporator and the heated portion of the suction conduit for selectively trapping refrigerant liquid or releasing said trapped refrigerant liquid and a single means for heating said storage means and the refrigerant liquid flowing in said evaporator when refrigerant liquid is released by said storage means.

6. A refrigerating circuit for selectively refrigerating or heating an evaporator, said circuit comprising an evaporator having an inlet and an \outlet, a compressor, a condenser, a conduit for conducting compressed refrigerant vapor from said compressor to said condenser, a liquid line including a pressure-reducing device for con-v ducting refrigerant liquid from said condenser to the inlet of said evaporator, a suction conduit connecting the outlet of said evaporator with said compressor, means for heating a portion of said suction conduit, said means comprising a heat exchanger between the conduit carrying compressed refrigerant vapor from said com` pressor and said portion of the suction conduit,

storage means located in said circuit intermedi- 30 ate the inlet of said evaporator and the heated portion of the suction conduit for selectively trapping refrigerant liquid or releasing said 6 trapped refrigerant liquid and means for heating said storage means during the time refrigerant liquid is being released therefrom.

7. A refrigerant circuit for selectivelyfre'frigerating or heating an evaporator, said. circuit comprising an elongated evaporator tube having an inlet end and an outlet end, a compressor. a condenser for receiving compressed refrigerant vapor from said compressor, a liquid line including a pressure-reducing device for conducting refrigerant liquid from said condenser to the inlet end of said evaporator tube, storage means communicating with the outlet end of said evaporator tube for selectively trapping refrigerant liquid or releasing said trapped refrigerant liquid, said evaporator tube having a portion o f the inlet end thereof arranged in heat-transfer relationship with said storage means, a suction conduit connecting said storage means and said compressor, means for heating a portion' o f said suction conduit and heating means for warming the inlet end of said evaporator tube.

GRAHAM S. McCLOY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,348,784 Buhler May 16, 1944 2,459,173 McCloy Jan. 18, 1949 2,487,662 McCloy Nov. 8, 1949 

